IMPRES: integrated monitoring for processor reliability and security

Security and reliability in processor based systems are concerns requiring adroit solutions. Security is often compromised by code injection attacks, jeopardizing even 'trusted software'. Reliability is of concern where unintended code is executed in modern processors with ever smaller feature sizes and low voltage swings causing bit flips. Countermeasures by software-only approaches increase code size by large amounts and therefore significantly reduce performance. Hardware assisted approaches add extensive amounts of hardware monitors and thus incur unacceptably high hardware cost. This paper presents a novel hardware/software technique at the granularity of micro-instructions to reduce overheads considerably. Experiments show that our technique incurs an additional hardware overhead of 0.91% and clock period increase of 0.06%. Average clock cycle and code size overheads are just 11.9% and 10.6% for five industry standard application benchmarks. These overheads are far smaller than have been previously encountered.